If you say that 3 straight sticks can simulate the letter C to represent the roman numeral for 100, then, by logical extension, you can also say that 4 straight sticks can simulate the roman D for 500.But then, it would look like a perfect square. So, how would you tell if it's a D o an O ? If I were to use straight sticks to simulate the roman C for 100, I'd rather use just 2 sticks, likeso: "<" — e.g.: Sparta<us, in the same way that V is used instead of U as in SENATVS.So, D would be something like this: "i>", using 3 straight sticks.

As to the presence of that short horizontal line ( ¯ ) over a roman numeral, simply means that the numeral is to be multiplied by 1,000, so that if you have 3 sticks, you can indicate any of these values: 9, 10, 11 or 10,000. A parenthesis ( ) can be used for the same effect — e.g.:(X) = 10,000; (L) = 50,000, etc. 2011 is: MMXI or (II)XI.